Telephone-exchange system



L. MEADE. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JULYI4, I920.

Patented May 16, 1922.

i m w z H w r 2 wi d-[- 0 fl Z 1H1!- 2 l2 4 2%: Z2 2 earn-tr HENRY L. IIJIEADE, OF NEW YORK, N, Y, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed July l,

To aZZ- whom it may concern:

Be it known that I, HENRY L. NIEADE, a citizen'of the United States, residing at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Telephone-EX- change Systems, of which the following is a full, clear, concise, and exactdescription.

This invention relates to telephone exchange systems and more particularly to systems in which a. number of subscribers may be connected together for common con versation with each other and a calling subscriber.

It frequently happens that an executive in charge of a department in a business organization may desire to convey by telephone to eachv of his assistants some information of common interest. In such cases it is advantageous to establish quickly a common connection between the executives vtelephone and all of the telephones of his assistants, thereby avoidingthe loss of time and inconvenience which would result from establishing an individual connection with each assistant. a

It is the object of this invention to provide an improved system of this character, which will be inexpensive and simple to operate, and, which will permit any indi vidual telephone of the system to be placed in common connection with a group oi associated telephones, as Well as in separate connection with any other individual telephone.

To attain this object in accordance with one feature of the invention a circuit, arrangement is providedso that a common connection with a group of telephone lines may be established in exactly thesame routine manner .as an individual connection with a particular telephone line. Another feature of this invention resides in a circuit arrangement by which any individual telephone in the associated group may be placed in common connection with all, of the. remaining telephones of the group. [l

In accordance with still anotherfeat'ure, an arrangement is employed whereby it is possible to place separate groups of associat'ed telephones in common connection.

These and other features not specifically Specification of Letters Extent. Paffigyd'tgd m is 1922 1920. Serial No. 396,133.

7, may establish a commonconnection withthe subscriber at station 13 and another subscriber whose line terminates at jack 2. The link circuit C may be of any well known type, the station apparatus therefor being omitted since it is unessentialtto' a proper understanding of the invention. f

It is thought that the inventionwill be more fully COZHPI'QilBllClQd by the following description of the operation of the system illustrated bythe drawing. Assuming that the subscriber at station 12 desires an individual connection with the subscriber at station 13, whose telephone line terminates at jack 1, the removal of his receiver from the hook will operate the line relay 30over an obvious circuit, thereby causing the illumination of the lamp 31. The operator will then insert plu 32 of the link circuit G into jack 83, disconnecting the line relay 30 at i the. tip and ring contacts of the jack. Lamp I ,31 will be extinguished on the release oi relay 80. The supervisory relay 35 operates over a circuit including the apparatus at station 12 so that lamp 36 is shunted by resistance 37 to prevent its illumination by current flowing through resistance 88 and the sleeve contacts of plug 32 and jack The operator, after operating listening key 27 andhaving ascertained that telephonic connection is desired with the subscriber at station 13, will insert plug 26 of link circuit G into ack 1. tion of conductors 17 .and 19 from conductors 2S and 29 at the tip and ring contacts of the jack respectively. The operator will now actuate the ringing key 10, to apply a source of ringing current1G to the ring strand of the link circuit C and ground to This will cause a disconnecthe tip strand. Ringing current will accordiiiigly be sent over conductors 28 and 29, operating the bell of the telephone Of the station When the operator inserted plug 26 into jack 1, the supervisory lamp 9 was illuminated over the following path: from grounded battery through lamp 9, resistance 15, sleeve contacts of plug 26 and jack 1 to ground. Vv'hen the subscriber at station 13, in response to the calling signal, removes his receiver from the hook, and the ringing key 10 has been released, a circuit path. is completed as follows: from grounded battery through the winding of supervisory relay 11, lower normal contact of: ringing key 10, ring contacts of plug 26 and jack 1, conductor 29, telephone apparatus'at station 13, conductor 28, tip contacts 0t jack 1 and plug 26 upper normal contact of key 10, to ground. Supervisory relay 11 is accordingly actuated and shunts the lamp 9 by a resistance 14, thereby extinguishing it. The subscribers at stations 12 and 13 are now free to converse over an obvious circuit path which i similar to that ordinarily used for common battery systems. On completion of the conversation the subscriber at station 13 will restore his receiver to the hook, thereby opening the circuit through the supervisory relay 11, to remove the shunt 1a from lamp 9, again causing its illumination. Similarly when the subscriber at station 12 restores his receiver, the supervisory lamp 36 will glow due to the release of relay 35. The operator will now restore all apparatus to normal by removing plugs 32 and 26 from jacks 33 and 1. respectively.

Assuming now that the subscriber at station 12 desires a simultaneous connection with the subscribers whose lines terminate at jacksl and 2, he will remove his receiver from the hook and signal the operator in control of the link circuit C. The operator, being informed that a common connection is desired with subscriber at station 13 whose line terminates 011 jack 1. and with the subscriber whose line terminates on ack 2, will insert the plug 26 of link circuit G into grouping jack 7, which is associated with the subscribers line jacks 1 and 2. The station apparatus for the line terminating on jack 2 has not been shown in order to simplify the drawing. However, any usual arrangement such as shown for tation 13 may be used. The jack 7 may be associated with other lines, not shown, but which may be connected in a similar manner. Relay {3 is operated over the following circuit: from grounded battery, through lamp 9, resist-- ance 15, sleeve contacts of plug 26 and jack 7, and winding of relay 6 to ground. Conductor 18 is disconnected at the right-hand normal contact of relay 6 from grounded battery, and connected at the middle alternate contact of such relay to the ring contact of jack 7. Conductor 17 is disconnected from ground at the left-hand normal contact of relay 6, and connected to the tip contact of ack 7 at the lefthand alternate contact of such relay. Relay 5 operates over an obvious circuit and connects conductor 18 to conductors 19 and 20 by means of its riglithand and middle alternate contacts, respectively. The operator then actuates ringing key 10 completing a circuit from the source of signaling current 16, through the lower alternate contact of key 10, the ring contacts of plu 26 and jack 7, the middle a ternate contact oi relay 6, the common conductor 18, thence in parallel through right-hand andmiddle alternate contacts of c relay 0, the conductors 19 and 20, the normally closed ring contacts of acks land 2,

the associated conductors of the line circuits such as conductor 29, the ringers at the substation of the line circuits such as at station 13, the other conductor of each line circuit, such as conductor 2, and the normally closed tip contacts oi" the jacks 1 and'2 to the common conductor 17' and thereafter through the left-hand contact of relay (3, the tip the upper alternate contact of key 10 to ground. The current in this circuit will operate the usual ringers of the station on the lines terminating at jacks 1 and 2, and of the stations on any other lines which may be associated with jack 7.

lVhen relay 5 operated, connecting conductor 18 to conductor 19, the windings of the line relays 3 and at, associated with jacks 2 and 1, respectively, were short-cir'cuited over obvious circuit paths through the middle and right-hand alternate contacts of relay This short-cireuiting of the line relay windings provides low resistance paths for the ringing and batter I currents and avoids the opera'tion'ol such relays and the lighting of the line lamps 1 0 and 8, to give false signals. The subscribers will remove their receivers, thereby establishing telephonic connection with the calling subscriber at station 12. For the subscribers station 13, a circuit path may be traced as follows: from grounded battery through the winding of supervisory relay 11, lower normal contact of key 10, ring contacts of plug 26 and jack 7, middle alternate contact of relay 6. common conductor 18, right-hand contact of relay 5, conductor 19, normal ring contactof jack 1, conductor 29, through the telephone set at station 13, conductor 28, normal tip contact of jack 1, common conductor17, left-hand alternate contact of relay 6, tip contacts of jack 7 and plug 26, and upper normal contact of key 10 to ground. Relay 11 will. beoperjated, extinguishing lamp 9 by shunting it with resistance 14-. The other subscribers stations associated with jack 7 will be connected in circuit in a similar mancontacts 0t jack 7 and pl'ug 26 and.

ner through other contacts of relay 5 and the normal contacts of their individual jacks; It will now be evident that each called subscriber is free to converse with the calling subscriber and with each of the other called subscribers. Upon the completion of. the conversation," each subscriber,on replacing his receiver on the switchhook, willrdiscontinue the supply of current from the cord circuit through the apparatus at his station, and when all of the associated subscribers have finally replaced their receivers, supervisory relay 11 will be released, and lamp 9 will be lighted in the same manner as previously described in connection withthe establishment of an individual connection. Upon observing the disconnect signal, the operator will withdraw the plug 26 from jack 7, causing the release ofrelay 6 and consequently the release of relay 5', thereby restoring all apparatus to normal.

It is evident that the system possesses flexibility in that a variable number of jacks to which subscribers lines are connected may be connected in association for common talking and ringing.- For instance, another jack may be connected to conductors 21 and 22 and one terminal of the corresponding line relay to conductor 25 'inthe same way as shown for jacks 1 and 2. For each additional jack in the group there must be added to relay 5 an additional contact which would be associated with conductors such as 23 and 24 connected to conductor 18. Independently of the grouping ack 7 each'associated subscriber may signal the operator and obtain connection with any subscriber not in the associated group, with any other subscriber in the group, or with all other subscribers of the group for common conversation. e

To establish a connection with any nonassociated, station such as 12, the subscriber at station 13 will removethe receiver from the hook and thereby actuate the line relay 4 over the following path: from grounded battery, through the right-hand normal contact of relay 6, common conductor 18, winding of relay 1, normal ring contact of jack 1, conductor 29, telephone set at station 13, conductor 28, normal tip contact of jack 1, com- I mon conductor 17 1eft-hand normal contact of relay 6 to ground. The lamp Swill then be illuminated over an obvious circuit. The

operator will then insert into jack 1 plug 32 of the answering end of the link circuit C.

This will cause the normally closed tip and with a grouping jack, as jack 7.

jack 33, which will similarly cause the dis- I connection of: line relay 30. Upon com-' pletion of the conversation, supervisory lamps-9 and 36 will be lighted by release of the relays 11 and 35, respectively.

It the subscriber at station 13 desires. connection with the associated subscribers line connected at ack 2, the plug 32 will be inserted into jack 1, and the plug 26 into jack 2. The tip and ring contacts at each jack will then open, disconnecting conductors 17-, 19 and 2O. This will permit conversation to be held through the linkcircuit over an obvious circuit path, independently of all associated apparatus. 011 the completion of the conversation, the supervisory lamps will be lighted in the usual manner, and upon withdrawal of the plugs from jacks 1 and 2, all apparatus will be'restored to normal.

If the subscriber at station 13 desires a common connection with all other associated subscribers served by the grouping jack 7, he will signal the operator in the usual way by removing his receiver from the hook,

causing the lighting of the line lamp 8. The operator'will insert plug 32 into jack 1, andon ascertaining that acommon connection is desired, will insert plug 26 into jack 7 which will establish a. telephonic connection of subscriber at ciated subscribers in exactly the same manner as connection was established between the subscriber at station-12 and the associated subscribers, as explained in detail above. In this case, however, the subscriber at station 13 will converse with the other,

to establish a common telephonicconnection between two groups of associated subscribers interconnected, asshown on the drawing, the individual subscribers being provided with jacks, as ack's 1 and 2 oi? the group, and g If the sub scriber at station 13 should desire acornmon connection with the other" subscribers of his own group, and a common connection with allot the subscribers of another'group, he would inform the operator of this fact. She would then insert plug 26 into the grouping jack of the called group of associated subscribers, and would then remove the answering 'plug'32 from jack 1, -into which it was inserted in response to the signal of subscriber 13 andthen insert it into the grouping jack '4', having previously requested the subscriber at station 13 to hang up his receiver until called. Each end of the link circuit C isnow plugged into a respective grouping jack such as jacki'.

station 13 through the link circuit C to the other asso- The operator will then ring on both ends of the link circuit by meansiof ringing keys 1.0 and and allthe associated subscribers of each group will be simultaneouslycalled, and upon removing their receivers from the switchhooks, a common conversational path will be established.

In a similar manner itis possible for any group subscriber to converse with all others of his own group in commonwith one subscriber of another group or to converse with all the subscribers otanother group.

The foregoing description illustrates one method by which a calling subscriber may obtain a common connection with a number of associated subscribers. It is evident, however, that the particular arrangement shown .may be departed from in various ways and still be within the scope of this invention. Other variations in circuit arrangements will'vbe readily obvious to those skilled in the art.

What is claimed is:

1. In a telephone exchange system, a group of associated subscribers lines, a-terminal jack for each subscribers line, a grouping jack associated with all of the lines of the associated subscribers, a cord circuit for connecting any two jacks, and means for establishing through the grouping jack a common conversational connection between any one of the associated subscribers lines and'the remaining subscribers lines in said group.

2. In a telephone exchange systenna plurality of individual subscribers lines terminating at a central office, a group of associated subscribers lines, means for establishing a conversational connection between any one of said plurality of subscribers lines and said group of associated subscribers lines, a line lamp atvthe central office connected to each associated subscribers line, and means for automatically disabling said line lamp previous to the establishing of said conversational connection.

3. In a telephone exchange system, a plu- -rality of individual subscribers lines, a

group of associated subscribers lines, a terininal ack for each subscribers line, a grouping ja'ck associated with all of the lines otthe associated subscribers lines, a cord circuit for connecting any two jacks, means for establishing through the grouping jack a common conversational connection between one of said plurality of individual subscribers lines and the group of associated subscribers lines, individual line signaling means connected to the line of each associated subscribers line, and means for disabling said individual'line signaling means responsive to the connection of the cord circuit with the grouping ack.

i. In a telephone exchange system, a group of associated subscribers lines a terminal jack toreach subscribcrs line, a grouping jack associated with all of the associated subscribers lines, a cord circuit for connec ing any two jacks, means for establishing through the grouping jack a common conversational connection between any onero't the associated subscribers lines andthe re maining subscriberslines in said group, individual line signaling means connected to each of the associated subscribers lines, and means for disabling said .individualline signaling means responsive to theconncction O'tthe cord circuit with the grouping jack.

5. In a telephone exchange system, a plurality of individual subscribers lines, a group of associated subscribers lines a terminal ack for each subscribefsline,a grouping jack associated with allot the lines of the associated subscribers lines a cord circuit for. connecting anyvtwo j aclrs, means for establishing through the grouping jack a common conversational connection between one of said plurality of individual subscribers lines and the group of associated subscribers lines, a source of potential tor the linecircuit oft theassociated subscribers linesnormally connectedthereto, and means for disconnecting said source responsive to the connection of the cord circuit with the grouping ack.

6. Ina'telephone exchangesystcnna group of associated subscribers lines, a terminal jack for each subscribers line, a grouping jaclrassociated with all rot ,thelines oi the associatedsubscribers, a cord CllCUlilffOl connectingany two jacks, means for establishing through the grouping jack a common conversational connection between any one of ,the associated subscribers lines I and the remaining subscribers lines in said group, a source of potential for the line circuits of the associated subscribers 'lines normally connected thereto, and 11161111811 01 disconnecting said source responsive tothe connection ofthe cord circuit with the grouping aclr.

7. In a telephone exchange system, a plu rality of individual subscribers lines, a group oiiassociatedsubscribers lines. a teriinal jack for each subscribers line, a grouping jack associated withallot the as sociated subscribers"lines, a cordcircuit for conncctingany two, jacks. means for estab lishing through thegrouping jack a common conversational connection between one of said plurality of individual subscribers lines andthe group oi": associated subscribers lines, individual line signaling vmeans connected to each line of the group and means tor shunting said individual line signaling means responsive to the connection of thecord circuit withthe grouping jack.

8. In a telephone eXchangesystem a group of associated subscribers lines a terminal jack for each subscribers line a grouping jack associated with all of the lines of the group, a cord circuit for connecting any two jacks, means for establishing through the grouping jack a common conversational connection between any one of the lines of the group and the remaining lines in said group, individual line signaling means connected to the line of each line of the group, and

means for shunting said individual line signalingvmeans responsive to the connection of the cord circuit With the grouping jack.

In Witness whereof, I hereunto subscribe my name this 1st day of July, A. D., 1920.

"HENRY MEADE. 

